Design of simultaneous high-Q and high-sensitivity photonic crystal refractive index sensors

Sensitivities (S) and quality factors (Q) have been trade-offs in label-free optical resonator sensors, and optimal geometry that maximizes both factors is under active development. In this paper, we demonstrate that the nano-slotted parallel multibeam cavity possesses unexplored high S and high Q. We achieve S > 800 nm/RIU (refractive index unit) and Q > 10(7) in liquid at telecom wavelength range when absorption is neglected. To the best of our knowledge, this is the first geometry that features both high S and Q factors, and thus is potentially an ideal platform for refractive index-based biochemical sensing. (C) 2013 Optical Society of America